Method of manufacturing an electronic device and electronic device manufactured thereby

ABSTRACT

Various aspects of this disclosure provide a method of manufacturing an electronic device and an electronic device manufactured thereby. As a non-limiting example, various aspects of this disclosure provide a method of manufacturing an electronic device, and an electronic device manufactured thereby, that utilizes ink to form an intermetallic bond between respective conductive interconnection structures of a semiconductor die and a substrate.

CROSS-REFERENCE TO RELATED APPLICATIONS/INCORPORATION BY REFERENCE

This patent application is related to U.S. patent application Ser. No.14/963,037, filed on Dec. 8, 2015, and titled “Transient InterfaceGrading Bonding for Metal Bonds,” which is hereby incorporated herein byreference in its entirety.

BACKGROUND

Present semiconductor devices and methods for manufacturing electronicdevices are inadequate, for example resulting in manufacturing processesthat are too time-consuming, involve too many steps, and/or are toocostly, resulting in electronic device with unreliable connections, withinterconnection structures having suboptimal dimensions, etc. Furtherlimitations and disadvantages of conventional and traditional approacheswill become apparent to one of skill in the art, through comparison ofsuch approaches with the present disclosure as set forth in theremainder of the present application with reference to the drawings.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 shows a flow diagram of an example method of manufacturing anelectronic device, in accordance with various aspects of the presentdisclosure.

FIGS. 2A to 2F show cross-sectional views illustrating various steps ofa method of manufacturing a semiconductor device, in accordance withvarious aspects of the present disclosure.

FIGS. 3A to 3B show illustrative cross-sectional drawings and/or imagesof an electronic device in accordance with various aspects of thepresent disclosure.

SUMMARY

Various aspects of this disclosure provide a method of manufacturing anelectronic device and an electronic device manufactured thereby. As anon-limiting example, various aspects of this disclosure provide amethod of manufacturing an electronic device, and an electronic devicemanufactured thereby, that utilizes ink to form an intermetallic bondbetween respective conductive interconnection structures of asemiconductor die and a substrate.

DETAILED DESCRIPTION OF VARIOUS ASPECTS OF THE DISCLOSURE

The following discussion presents various aspects of the presentdisclosure by providing examples thereof. Such examples arenon-limiting, and thus the scope of various aspects of the presentdisclosure should not necessarily be limited by any particularcharacteristics of the provided examples. In the following discussion,the phrases “for example,” “e.g.,” and “exemplary” are non-limiting andare generally synonymous with “by way of example and not limitation,”“for example and not limitation,” and the like.

As utilized herein, “and/or” means any one or more of the items in thelist joined by “and/or”. As an example, “x and/or y” means any elementof the three-element set {(x), (y), (x, y)}. In other words, “x and/ory” means “one or both of x and y.” As another example, “x, y, and/or z”means any element of the seven-element set {(x), (y), (z), (x, y), (x,z), (y, z), (x, y, z)}. In other words, “x, y and/or z” means “one ormore of x, y, and z.”

The terminology used herein is for the purpose of describing particularexamples only and is not intended to be limiting of the disclosure. Asused herein, the singular forms are intended to include the plural formsas well, unless the context clearly indicates otherwise. It will befurther understood that the terms “comprises,” “includes,” “comprising,”“including,” “has,” “have,” “having,” and the like when used in thisspecification, specify the presence of stated features, integers, steps,operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, integers, steps,operations, elements, components, and/or groups thereof.

It will be understood that, although the terms first, second, etc. maybe used herein to describe various elements, these elements should notbe limited by these terms. These terms are only used to distinguish oneelement from another element. Thus, for example, a first element, afirst component or a first section discussed below could be termed asecond element, a second component or a second section without departingfrom the teachings of the present disclosure. Similarly, various spatialterms, such as “upper,” “above,” “lower,” “below,” “side,” “lateral,”“horizontal,” “vertical,” and the like, may be used in distinguishingone element from another element in a relative manner. It should beunderstood, however, that components may be oriented in differentmanners, for example a semiconductor device may be turned sideways sothat its “top” surface is facing horizontally and its “side” surface isfacing vertically, without departing from the teachings of the presentdisclosure.

It will also be understood that terms coupled, connected, attached, andthe like include both direct and indirect (e.g., with an interveningelement) coupling, connecting, attaching, etc., unless explicitlyindicated otherwise. For example, if element A is coupled to element B,element A may be indirectly coupled to element B through an intermediatesignal distribution structure, element A may be directly coupled toelement B (e.g., adhered directly to, soldered directly to, attached bydirect metal-to-metal bond, etc.), etc.

In the drawings, the dimensions of structures, layers, regions, etc.(e.g., absolute and/or relative dimensions) may be exaggerated forclarity. While such dimensions are generally indicative of an exampleimplementation, they are not limiting. For example, if structure A isillustrated as being larger than region B, this is generally indicativeof an example implementation, but structure A is generally not requiredto be larger than structure B, unless otherwise indicated. Additionally,in the drawings, like reference numerals may refer to like elementsthroughout the discussion.

Various aspects of the present disclosure relate to a method ofmanufacturing (or fabricating) an electronic device (e.g., asemiconductor device, integrated circuit, etc.), and an electronicdevice manufactured thereby.

Along with current tendencies toward a lightweight, slim and small-sizedproduct, it is generally desirable for electronic devices that areincorporated into such products to have a reduced size and to haveincreased functionality. To meet electronic device goals, variouselectronic device packaging technologies have been developed, some ofwhich may for example include the incorporation of multiplesemiconductor dies into a single electronic device package. Suchpackages may also, for example, include two-dimensional orthree-dimensional arrays of semiconductor dies.

Some of such packaging technologies may, for example, utilize solderbumps, in addition to or instead of wire bonding technology for theattachment of electronic components to substrates and/or for theattachment of electronic components directly to each other. Such solderbumping technology, however, has various limitations (e.g., sizelimitations in any or all dimensions, process complexity limitations,reliability limitations, etc.).

Accordingly, various aspects of the present disclosure provide a methodof manufacturing (or fabricating) an electronic device (e.g., asemiconductor device), and an electronic device manufactured thereby.Such method may, for example, comprise providing a semiconductor diehaving metal bumps (or any of a variety of conductive interconnectionstructures) protruding from one surface thereof, dipping tips of themetal bumps into metal ink, aligning the semiconductor die on asubstrate (many examples of which are provided herein), and bonding thesemiconductor die to the substrate through thermocompression bonding.

The metal ink may, for example, be provided in a state in whichconductive metal ions, metal molecules, and/or metal particles aredispersed in a solvent. The conductive metal ions, the metal molecules,and/or the metal particles may, for example, comprise or be madeentirely of silver (Ag). The metal ink may, for example, be provided inan ink holder, and the metal bumps of the semiconductor die may bedipped (e.g., downward) into the metal ink in a state in which they areoriented to face downward.

Also, for example, thermocompression bonding may be performed on themetal bumps at a temperature between 25° C. and 400° C. (or in a rangefrom 25° C. to 400° C.). Additionally, for example, thermocompressionbonding may be performed on the metal bumps by applying a pressurebetween 0.1 bar and 20 Kbar (or in a range from 0.1 bar to 20 Kbar) tothe metal bumps.

In an example implementation, after performing a cleaning operation onthe semiconductor die, a die-handling apparatus (e.g., a diepick-and-place tool, component pick-up device, stage, etc.) may beutilized to manipulate (e.g., pick up, move, dip, set down, etc.) thedie, for example to dip the die into the metal ink.

Also for example, the semiconductor die may be positioned to align themetal bumps of the semiconductor die to respective metal bumps (or anyof a variety of types of conductive interconnection structures) on asubstrate (many examples of which are provided herein).

Bonding may then, for example, be performed to bond the semiconductordie to the substrate. For example, thermocompression bonding may beperformed in a state in which the metal bumps of the semiconductor dieare brought into contact with the metal bumps of the substrate, forexample with the metal ink positioned between corresponding metal bumpsof the semiconductor die and the substrate.

Various aspects of this disclosure also provide an electronic device(e.g., a semiconductor device, etc.) manufacturing utilizing any or allof the steps discussed herein. For example, a semiconductor device maycomprise metal bumps protruding from one side (or surface) thereof; asubstrate (many examples of which are provided herein) including metalbumps corresponding to the metal bumps of the semiconductor die; and abonding region formed by bonding the metal bumps of the semiconductordie to the metal bumps of the substrate, wherein the bonding regioncomprises an intermetallic compound.

The intermetallic compound may, for example, be formed using the metalbumps of the semiconductor die, the metal bumps of the substrate, andthe metal ink formed between the metal bumps of the semiconductor dieand the metal bumps of the substrate. The metal ink may, for example,form or enhance the forming of the intermetallic compound, and may beprovided in a state in which conductive metal ions, metal molecules,and/or metal particles are dispersed in a solvent. In an exampleimplementation, the conductive metal ions, the metal molecules, and/orthe metal particles may comprise or be made entirely of silver (Ag).

Various aspects of the present disclosure provide a method ofmanufacturing an electronic device, where the method comprises:providing a substrate comprising a substrate conductive interconnectionstructure; providing a semiconductor die comprising a die conductiveinterconnection structure protruding from a first surface of the die;coating at least a first surface of the die conductive interconnectionstructure and/or at least a first surface of the substrate conductiveinterconnection structure with an ink that comprises metal; and bondingthe first surface of the die conductive interconnection structure andthe first surface of the substrate conductive interconnection structure.The substrate may, for example, comprise a wafer or panel of substrates(e.g., prior to singulation).

Providing the semiconductor die may, for example, comprise providing asemiconductor wafer comprising the semiconductor die and one or moreother semiconductor dies, where the method comprises after saidproviding (or as part of said providing), singulating the semiconductordie from the provided wafer. The die conductive interconnectionstructure may, for example, comprise a metal pillar (or post). The firstsurface of the die conductive interconnection structure may, forexample, be planar or non-planar.

The coating of the die conductive interconnection structure may, forexample, comprise coating at least the first surface of the dieconductive interconnection structure with the ink. The coating of thedie conductive interconnection structure may, for example, comprisedipping at least a first respective surface of the die conductiveinterconnection structure and/or a first respective surface of thesubstrate conductive interconnection structure in the ink.

The method may, for example, comprise prior to performing the coating,singulating the semiconductor die from a semiconductor wafer and, saidcoating may comprise coating at least a first respective surface of thedie conductive interconnection structure of the singulated semiconductordie with the ink. The metal of the ink may, for example, comprise metalions, metal molecules, and/or metal particular dispersed in a solvent.The method may, for example, comprise prior to performing the coating,forming the ink on an ink carrier structure, wherein the coatingcomprises dipping at least the first surface of the die conductiveinterconnection structure in the ink.

Various aspects of the present disclosure provide a method ofmanufacturing an electronic device, where the method comprises providinga substrate comprising a substrate conductive interconnection structure;providing a semiconductor die comprising a die conductiveinterconnection structure protruding from a first side of the die; andpressing a first surface of the die conductive interconnection structureand a first surface of the substrate conductive interconnectionstructure together with at least one layer of the ink at an interfacebetween the first surface of the die conductive interconnectionstructure and the first surface of the substrate conductiveinterconnection structure.

The pressing may, for example, comprise performing the pressingutilizing a thermocompression bonding process. The bonding utilizing thethermocompression bonding process may, for example, comprise performingthe thermocompression bonding without ultrasonic vibration and/orwithout solder. The thermocompression bonding process may, for example,comprise performing thermocompression bonding at a temperature between25° C. and 400° C. and/or at a pressure between 0.1 bar and 20 Kbar.

The bonding may, for example, comprise pressing the first surface of thedie conductive interconnection structure and the first surface of thesubstrate conductive interconnection structure together with only theink between the first surface of the die conductive interconnectionstructure and the first surface of the substrate conductiveinterconnection structure.

Various aspects of the present disclosure provide an electronic device,for example a semiconductor device, manufactured in accordance with anyor all of the manufacturing process steps discussed herein.

Various aspects of the present disclosure provide an electronic devicethat comprises: a substrate comprising a substrate conductiveinterconnection structure; a semiconductor die comprising a dieconductive interconnection structure; and a bonding region between afirst end of the substrate conductive interconnection structure and afirst end of the die conductive interconnection structure, wherein thebonding region comprises: metal from the first end of the die conductiveinterconnection structure; metal from the first end of the substrateconductive interconnection structure; and metal from an ink.

The first end of the substrate conductive interconnection structureand/or the first end of the die conductive interconnection structuremay, for example, be non-planar. The substrate conductiveinterconnection structure may for example comprise copper, the dieconductive interconnection structure may for example comprise copper,and the metal from the ink may for example comprise silver. The bondingregion may, for example, comprise an intermetallic bond that comprisesthe metal from the first end of the die conductive interconnectionstructure, the metal from the first end of the substrate conductiveinterconnection structure, and/or the metal from the ink. The bondingregion may also, for example, comprise a first region comprising anintermetallic bond between a first interconnection structure and metalfrom the ink, a second region comprising only metal from the ink, and athird region comprising an intermetallic bond between a secondinterconnection structure and metal from the ink.

Various aspects of the present disclosure will now be described indetail with reference to the accompanying drawings such that they may bereadily practiced by those skilled in the art. Note that commonreference numerals may be used throughout the drawings and the detaileddescription to indicate the same (or similar) elements.

FIG. 1 shows a flow diagram of an example method 101 of manufacturing anelectronic device (e.g., a semiconductor device, etc.), in accordancewith various aspects of the present disclosure. FIGS. 2A-2F showcross-sectional views of an example electronic device (e.g., asemiconductor device, etc.) during and/or after manufacturing inaccordance with the example method 101 of FIG. 1. The followingdiscussion will generally refer to FIG. 1 and to FIGS. 2A-2F together.

Referring to FIG. 1, the example method 101 of manufacturing asemiconductor device may comprise: (140) providing a semiconductor die,(150) cleaning the semiconductor die, (160) handling the semiconductordie, (170) coating an interconnection structure with ink, (180)providing a substrate, and (190) bonding the semiconductor die to thesubstrate. Various blocks (or steps, stages, processes, etc.) of theexample method 101 illustrated FIG. 1 will be now be described withreference to FIGS. 2A-2F

The example method 101 may begin executing at block 135. The examplemethod 101 may begin executing in response to any of a variety of causesor conditions, non-limiting examples of which are provided herein. Forexample, the example method 101 may begin executing in response toreceiving an electrical signal (e.g., from an upstream process, from acentral controller, etc.) to begin, upon arrival of any or all materialsnecessary to perform the method 101, upon user command, etc. Also forexample, the example method 101 may begin executing in response toreceiving operational flow from any other methods or method blocksdiscussed herein (or elsewhere). The scope of this disclosure should notbe limited by characteristics of any particular initiating cause orcondition.

The example method 101 may, at block 140, comprise providing thesemiconductor die. Block 140 may comprise providing the semiconductordie in any of a variety of manners, non-limiting examples of which areprovided herein. Various example aspects of block 140 are shown at FIG.2A.

Block 140 may, for example, comprise receiving a wafer 100 ofsemiconductor dies 110 (e.g., formed on an active surface of the wafer100). The wafer 100 may, for example, be provided attached to a carrieror stage (e.g., adhered to the carrier with adhesive, mounting tape ordie-attach tape, vacuum-held, mechanically clipped, etc.). The wafer 100may, for example, be provided in a non-diced state, a fully-diced state,or a partially-diced state. The wafer 100 may also, for example, beprovided in the form of a reconstituted wafer (e.g., with dies heldtogether with molding material or other dielectric material, etc.). Thewafer 100 may, for example, be provided in a state in which the wafer100 has been partially diced or fully diced, for example by partiallycutting through the wafer 100 or fully cutting through the wafer 100along dicing (or singulation or scribing) lines of the wafer 100. Notethat the wafer 100 may, for example, comprise a wafer or panel-shapedcarrier to which a plurality of previously-diced dies are attached.

In an example implementation, the wafer 100 may be provided with a sideof the wafer 100 (e.g., a back or inactive side, or a front or activeside), as a whole or as an array of individual singulated dies, mountedto a carrier with a mounting tape. Though not shown in FIG. 2A, such acarrier and mounting tape may, for example be positioned under the wafer100 as designated by label 105 in FIG. 2A.

The semiconductor die 110 (e.g., a plurality thereof, etc.) may, forexample, comprise characteristics of any of a variety of types of dies.For example, the semiconductor die 110 may comprise a processor, adigital signal processor (DSP), a networking processor, a powermanagement unit, an audio and/or video processor, a wirelesscommunication circuit, a system-on-chip (SoC) processor, a sensor orsensor processor, an application specific integrated circuit (ASIC), adiscrete logic device, a transistor, etc. Note that although thisdisclosure generally refers to semiconductor dies, the scope of thisdisclosure is not limited thereto. For example, the aspects of thisdisclosure also apply to passive electronic components (e.g., resistors,capacitors, inductors, etc.), micro-electro-mechanical system (MEMS)components, any combination of such components, etc. Also note that thedie 110 may also be (or comprise) a signal distribution structure. Forexample, the die 110 need not comprise functional electronic components,for example being entirely dedicated to the distribution of electricalsignals.

The semiconductor die 110 may, for example, comprise conductiveinterconnection structures for providing electrical contact with othercomponents (e.g., with other substrates, such as mother boards, packagesubstrates, interposers, signal distribution structures, other dies,other packaged electronic devices, etc.). Such conductiveinterconnection structures may, for example, extend from an active sideof the semiconductor die 110.

The conductive interconnection structures (e.g., as designated invarious drawings by label 111) may, for example, comprisecharacteristics of any of a variety of different types of conductiveinterconnection structures. For example, the conductive interconnectionstructures may comprise metal pillars or posts (e.g., copper pillars,etc.), conductive bumps or balls (e.g., copper bumps or balls, etc.),metal wires (e.g., die bonding wires, etc.), pads, etc.

In an example implementation, the conductive interconnection structuresmay comprise metal pillars (or posts). Such metal pillars may, forexample, each comprise a first end that faces away from thesemiconductor die 110 and with which electrical and/or mechanicalconnection is to made with another conductive interconnection structure(e.g., of a substrate, etc.). Such first end may, for example, be planar(e.g., parallel to a planar surface of the semiconductor die 110 fromwhich the conductive interconnection structure extends. Such first endmay also, for example, be concave or convex. Such a configuration isdiscussed in detail in U.S. patent application Ser. No. 15/387,016,filed Dec. 21, 2016, and titled “Semiconductor Product with InterlockingMetal-to-Metal Bonds and Method for Manufacturing thereof,” the entirecontent of which is hereby incorporated herein by reference in itsentirety. Such metal pillars (or posts) may, for example, be uncapped(e.g., not capped with a layer of solder or other reflowable material,not capped with a cap layer of any metal different from the metal of thepillar, etc.).

In general, block 140 may comprise providing the semiconductor die.Accordingly, the scope of this disclosure should not be limited bycharacteristics of any particular semiconductor die (or wafer) or bycharacteristics of any particular manner of providing a semiconductordie (or wafer).

The example method 101 may, at block 150, comprise cleaning thesemiconductor die. Block 150 may comprise performing such cleaning inany of a variety of manners, non-limiting examples of which are providedherein. Various example aspects of block 150 are shown at FIG. 2B.

In an example implementation, block 150 may comprise cleaning as leastone surface of a wafer 100 comprising any number of the semiconductordies 110. For example, block 150 may comprise cleaning the side of thewafer 100 from which the conductive interconnection structures extend(e.g., an active side of the wafer).

For example, block 150 may comprise performing the cleaning, at least inpart, by activating gases, such as argon (Ar), hydrogen (H₂) or oxygen(O₂), injected alone or in combination, into a plasma state usingelectrical energy to cause the same to collide with the wafer 100 (e.g.,including any conductive interconnection structures formed thereon). Inaddition to (or instead of) performing plasma cleaning, block 150 mayalso comprise cleaning by physical treatment or wet cleaning by chemicaltreatment.

Note that block 150 may comprise performing the cleaning at the waferlevel, at the individual die level, at the level of a panel on which aplurality of individual dies are held, etc.

Also note that, although not shown in FIG. 1, the cleaning may also beapplied to a substrate such as that provided at block 180.

In general, block 150 may comprise cleaning the semiconductor die.Accordingly, the scope of this disclosure should not be limited bycharacteristics of any particular manner of performing such cleaning.

The example method 101 may, at block 160, comprise handling thesemiconductor die. Block 160 may comprise performing such handling inany of a variety of manners, non-limiting examples of which are providedherein. Various example aspects of block 160 are shown at FIG. 2C.

For example, block 160 may comprise picking up an individual die 110from the wafer 100 (or carrier). As shown at FIG. 2C, a die-handlingapparatus 20 (e.g., a die manipulation tool, a die pick-and-place tool,a component pick-up device, a stage, etc.), or portion thereof, may beutilized to pick up one of the semiconductor dies 110.

In an example implementation in which the back surface of the wafer 100(or dies 110) is adhered to a stage (e.g., utilizing mounting tape,utilizing a vacuum, etc.) of the die-handling apparatus 20, block 160may comprise picking up an individual semiconductor die 110 using a diemanipulation tool 22 (e.g., a die pick-and-place tool, a die pick-uptool, or component pick-up device, etc.) approaching a front surface ofthe wafer 100. For example, the die manipulation tool 22 may comprise avacuum nozzle for picking up the semiconductor die 110. The apparatus 20may also, for example, comprise a die-eject tool 21.

Note that one or more die manipulation tools 22 may be utilized toorient the picked-up semiconductor die 110 in an orientation in whichthe active side of the semiconductor die 110, including conductiveinterconnection structures extending therefrom, is facing downward. Forexample, though an initial die pick-up operation may be performed with adie manipulation tool 22 at the front (or active) side of thesemiconductor die 110, the die 110 may then be transferred to anotherdie manipulation tool 22 that holds the semiconductor die 110 from theback side. Alternatively, the semiconductor die 110 may be originallyoriented back-side-up on the stage so that the die manipulation tool 22may initially pick up the semiconductor die 110 from the back side.

As shown in FIG. 2D, the die manipulation tool 22 may hold thesemiconductor die 110 from the back side so that the conductiveinterconnection structures 111 (e.g., metal pillars, metal bumps, etc.)face downward.

As discussed herein the conductive interconnection structures 111 mayprotrude from respective conductive pads of the semiconductor die 110(or may, for example, be extended pads of the semiconductor die 110). Asdiscussed herein with regard to block 140, the semiconductor die 110 maybe originally provided having such conductive interconnection structures111 and/or block 140 may comprise forming the conductive interconnectionstructures. In an example implementation, each of the conductiveinterconnection structures 111 comprises a metal pillar (or bump) thatprotrudes a predetermined length from a respective conductive pad on thefront (or active) surface of the semiconductor die 110.

Note that the conductive interconnection structures 111 may all protrudefrom the semiconductor die 110 a same distance. For example, aplanarization process may be utilized (e.g., at block 140 or anotherblock) to ensure that each of the conductive interconnection structures111 protrude a same distance from the semiconductor die 110.Alternatively, a tightly controlled process may be utilized whenoriginally forming such conductive interconnection structures 111 toensure that each of the conductive interconnection structures 111protrude a same distance from the semiconductor die 110.

As discussed herein, the conductive interconnection structures 111 maycomprise any of a variety of characteristics. For example, theconductive interconnection structures 111 may comprise metal pillars (orposts), metal bumps, conductive pillars (or posts), conductive bumps,conductive balls, etc. The conductive interconnection structures 111may, for example, be formed of copper (Cu), gold (Au), silver (Ag),aluminum (Al), equivalents thereof, alloys thereof, etc.

In general, block 160 may comprise handling the semiconductor die 110.Accordingly, the scope of this disclosure should not be limited bycharacteristics of any particular manner of handling a semiconductor dieor by characteristics of any particular semiconductor die.

The example method 101 may, at block 170, comprise coating one or moreconductive interconnection structures with ink. Block 170 may compriseperforming such coating in any of a variety of manners, non-limitingexamples of which are provided herein. Various example aspects of block170 are shown at FIGS. 2D-1 and 2D-2.

For example, as shown in FIG. 2D-1, block 170 may comprise dipping theconductive interconnection structures 111 that extend downward from thesemiconductor die 110 into an ink (e.g., a metal or metal-filled ink,etc.) that is provided in a dipping cavity 31 (or a well or a pool,etc.) of an ink holder 30. In an example implementation, the ink holder30 may be generally plate-shaped and may comprise an upper surface 35,dipping cavity 31 (or indentation, pool, well, etc.) formed in the uppersurface 35, and groove formed in at least one major surface (e.g., in atop surface, etc.). The ink may, for example, fill the dipping cavity31.

FIG. 2D-2 provides another example implementation of an ink holder 230.FIG. 2D-2 shows perspective and side views of the example ink holder230. The example ink holders 30 and 230 of FIGS. 2D-1 and 2D-2 may shareany or all characteristics. For example any of the characteristics ofthe example ink holder 30 may be incorporated into the example inkholder 230 and vice versa.

The example ink (or material) holder 230 of FIG. 2D-2 may, for example,comprise an ink (or material) tank 239 on an upper surface 235. Adipping cavity 231 (or indentation, well, pool, etc.) may be formed inthe upper surface 235. A perimeter groove 238 may be formed around theperimeter of the upper surface 235, along with a perimeter shelf 237.The perimeter groove 238 may, for example, accommodate ink flow (e.g.,of excess ink, etc.). In an example implementation, the dimension A maybe 6.5 mm, the dimension B may be 10 um, and the dimension C may be 6mm. Any of such dimensions may be modified in accordance with variousimplementation parameters. For example, dimension B (e.g., the depth ofthe ink cavity 213) may be set in accordance with the amount of inkdesired on the interconnection structures 111, with the amount ofmanufacturing variation in the co-planarity of the ends of theinterconnection structures 111, etc. For example, the dimension B may beset to be less than 8 um. Also for example, the dimension B may be setto be less than 5 um or less than 2 um. Additionally for example, invarious circumstances, a controllable thin coat of ink may be spread onthe upper surface 35 without utilizing a groove 31. In an exampleimplementation, the depth B of the dipping cavity 231 and/or thethickness of the ink may be in the range of 1 nm to 10 um. Additionally,though in a first implementation, the ink might only cover the bottomend surfaces of the interconnection structures 111, in otherimplementations the ink may also be present on side surfaces of theinterconnections structures 111 bordering such end surfaces. The dippingcavity 231 may comprise any of a variety of X/Y dimensionalcharacteristics.

The ink may be formed on the ink holder 30/230 in any of a variety ofmanners, for example by printing, spraying, dipping, spin-coating,vapor-depositing, squeegeeing, scraping, etc. The ink may, for example,be formed on the ink holder 30/230 (e.g., in the dipping cavity 31/231)to a predetermined depth that coincides with the amount of ink to beformed on the conductive interconnection structures 111 (e.g., within aparticular amount of manufacturing tolerance). For example, thepredetermined depth may be set such that, considering a maximum expected(or accepted) amount of non-coplanarity of the ends of the conductiveinterconnection structures, would still result in at least the endsurface of each of the conductive interconnection structures 111 beingcoated with the ink.

In an example implementation, before each application of ink onto theinterconnection structures 111, the ink cavity 31/231 may be filled withmetal ink. For example, the ink (or material) tank 239 (or reservoir)and/or the dipping cavity 231 may be moved horizontally relative to eachother (e.g., the ink cavity 231 may be moved back-and-forth under theink tank 239, the ink tank 239 may be moved back-and-forth over the inkcavity 231, etc.).

In an example implementation, at least the end surfaces of theconductive interconnection structures 111 may be covered with the ink.Note, however, that at least an end portion of the lateral sides of theconductive interconnection structures 111 may also be covered with theink.

As discussed herein, with the ink coated on the conductiveinterconnection structures 111 (or ends thereof), the conductiveinterconnections structures 111 may be stacked on and bonded tocorresponding conductive interconnection structures of a substrate(e.g., a circuit board, a mother board, a package substrate, aninterposer, an interposer formed on a semiconductor wafer or formed on aglass or metal plate, a signal distribution structure, a signaldistribution structure formed on a semiconductor wafer or formed on aglass or metal plate, another electronic package, another functionalsemiconductor die, etc.), for example utilizing thermocompressionbonding. To enhance the bonding, which may for example comprise asolderless metal-to-metal bond, the ink (e.g., a metal link, etc.) maybe formed of a metal ink material, for example comprising silver (Ag).For example, the ink may be formed (or provided) in a state in whichconductive metal ions, metal molecules or metal particles (e.g.,comprising silver (Ag), comprising only silver, etc.) are dispersed in asolvent (e.g., ethanol, anisole, hexylamine, etc.). For example, asopposed to solder paste, the ink may be free of tin, free of copper,and/or free of flux. Such formation may, for example, reduce oreliminate joint or bump integrity issues that are inherent or oftenpresent in copper-tin (Cu—Sn) type joints. It should be noted thatduring the bonding process, a portion of the ink may be forced out ofthe joint and create a slight conductive bulge protruding laterally fromthe joint. In an example implementation, the solvent of the ink (orother material) may all be removed from the final bonding joint, leavingonly the metal in the ink.

Since such bonding may be efficiently and reliably formed withoutreflowing solder, manufacturing efficiency and high reliability at afine pitch spacing may be achieved. The ink (or metal within) may, forexample, enhance electromigration. Also for example, when thethermocompression bonding is performed using the ink, enhancedelectrical characteristics (e.g., low resistivity, etc.) may be achievedbetween the conductive interconnection structures 111 of thesemiconductor die 110 and corresponding conductive interconnectionstructures of the substrate.

In the example implementations discussed herein, only a singlesemiconductor die 110 at a time is manipulated and coated with the ink.It should be understood that a plurality of such dies 110 (e.g., in anarray, in a reconstituted wafer, in a semiconductor wafer, in a panel,etc.) may be simultaneously coated.

Also, in the example implementations discussed herein, the conductiveinterconnection structures 111 of the semiconductor die 110 are coatedwith the ink. It should be understood that the corresponding conductiveinterconnection structures (e.g., of the substrate, etc.) may also (oralternatively) be coated with the ink. For example, a substratemanipulation tool may be utilized to dip conductive interconnectionstructures of a circuit board, mother board, packaging substrate,interposer, signal distribution structure, other die, etc., in the ink(or otherwise apply such ink).

In general, block 170 may comprise coating one or more conductiveinterconnection structures with ink. Accordingly, the scope of thisdisclosure should not be limited by characteristics of any particularmanner of coating with ink or of any particular type of ink.

The example method 101 may, at block 180, comprise providing asubstrate. Block 180 may comprise performing such providing in any of avariety of manners, non-limiting examples of which are provided herein.Various example aspects of block 180 are shown at FIG. 2E.

The substrate (e.g., the substrate 120 of FIG. 2E) may comprise any of avariety of characteristics. For example, the substrate may comprise acircuit board substrate, a mother board substrate, a package substrate,a cored or coreless substrate, a laminate substrate, an interposer, aninterposer formed on a semiconductor wafer or formed on a glass or metalplate, a signal distribution structure, a signal distribution structureformed on a semiconductor wafer or formed on a glass or metal plate, anelectronic component package (e.g., a stackable package, etc.), asemiconductor die, a signal distribution structure formed in asemiconductor die (or wafer), a substrate panel, a substrate wafer, etc.The substrate may, for example, be provided as part of a wafer ofsubstrates, a reconstituted wafer of substrates, a panel of substrates,etc.

The substrate 120 may, for example, be provided having conductiveinterconnection structures 121 already formed thereon, or block 180 maycomprises forming such structures. The conductive interconnectionstructures 121 may, for example, share any or all characteristics withthe conductive interconnection structures 121 of the semiconductor die110 discussed herein. The conductive interconnection structures 121 may,for example, comprise pads or lands of the substrate 120. The conductiveinterconnection structures 121 may, for example, comprise metal pillars(or posts), metal bumps, conductive pedestals, etc., of the substrate120.

In an example implementation (discussed herein) in which the conductiveinterconnection structures 111 have planar ends, the ends of theconductive interconnection structures 121 may also have planar ends. Inanother example implementation (discussed herein) in which theconductive interconnection structures 111 have convex ends, the ends ofthe conductive interconnection structures 121 may have concave ends. Instill another example implementation (discussed herein) in which theconductive interconnection structures 111 have concave ends, the ends ofthe conductive interconnection structures 121 may have convex ends.

Though as shown in FIG. 2E, the lateral dimensions of the conductiveinterconnection structures 111 and the conductive interconnectionstructures 121 are equal, this need not be the case. For example, theconductive interconnection structures 121 of the substrate 120 may belaterally wider than the conductive interconnection structures 111 ofthe semiconductor die 110 (e.g., in one-dimension, in two-dimensions,etc.).

Though as shown in FIG. 2E, the conductive interconnection structures121 of the substrate 120 and the conductive interconnection structures111 of the semiconductor die 110 are generally cylindrical-shaped (e.g.,with a circular cross-section), this need not be the case. For example,the conductive interconnection structures 111 and/or the conductiveinterconnection structures 121 may comprise cross-section(s) that areoval-shaped, rectangular-shaped, trapezoid-shaped, diamond-shaped, etc.

In general, block 180 may comprise providing a substrate. Accordingly,the scope of this disclosure should not be limited by characteristics ofany particular manner of providing a substrate or by characteristics ofany particular substrate or type thereof.

The example method 101 may, at block 190, comprise bonding thesemiconductor die to the substrate. Block 190 may comprise performingsuch bonding in any of a variety of manners, non-limiting examples ofwhich are provided herein. Various example aspects of block 190 areshown at FIG. 2E and FIG. 2F.

Referring to FIG. 2E, block 190 may comprise aligning the semiconductordie 110 (e.g., as held by the die manipulation tool 22) (e.g., theconductive interconnection structures 111 thereof), to the substrate 120(e.g., the conductive interconnection structures 121 thereof). As shownin FIG. 2E, the substrate 120 may be coupled to a carrier 40 (or stage).

Block 190 may, for example, comprise bringing corresponding end surfacesof the conductive interconnection structures 111 of the semiconductordie 110 into contact with corresponding end surfaces of the conductiveinterconnection structures 121 of the substrate 120. As shown in FIG.2E, at this point, there is a clear interface 125 between correspondingconductive interconnection structures 111/121. This interface 125 may,for example, comprise the ink that was coated on the conductiveinterconnection structures 111 at block 170.

Note that in instances where the opposite facing ends of the conductiveinterconnection structures 111/121 have non-matching sizes, or ininstances in which the conductive interconnection structures 111/121 areimperfectly aligned, there may be a portion of the ink that is notdirectly between the conductive interconnection structures 111/121. Insuch case, after the bonding is performed, there may be remnants of theink (e.g., metal ions, metal molecules, metal particles, solvent, etc.).Such remnants may, for example, be removed during a later cleaningprocess, may be encapsulated along with the conductive interconnectionstructures 111/121 during a later manufacturing step, etc.

Block 190 may then, for example, comprise applying heat and/or pressure(e.g., utilizing thermocompression bonding, etc.) to bond the conductiveinterconnection structures 111/121 to each other. In an exampleimplementation utilizing thermocompression bonding, such bondingprovides for the conductive interconnection structures 111 of thesemiconductor die 110 having the ink coated thereon and the conductiveinterconnection structures 121 of the substrate 120 to be bonded to eachother. Note that, as discussed herein, the conductive interconnectionstructures 121 of the substrate 120 may also (or alternatively) becoated with the ink. In an example implementation, block 190 maycomprise performing the bonding without the utilization of ultrasonicvibration and/or without the utilization of solder reflow (or withoutthe utilization of epoxy bonding). This may, for example, different fromother direct metal-to-metal bonding techniques (e.g., directcopper-to-copper bonding techniques, etc.), in which ultrasonic energyis used to enhance the bonding process.

In an example implementation utilizing thermocompression bonding, thetemperature of the thermocompression bonding may be between 25° C. and400° C. (or in a range from 25° C. to 400° C.). In this case, if thetemperature of the thermocompression bonding is higher than 25° C., anintermetallic compound is efficiently formed across interface 125between and/or into the conductive interconnection structures 111/121,where the intermetallic compound can include at least portions (e.g.,metal portions) of the ink diffused into interconnection structure111/121, thereby providing a high bonding strength. In addition, if thetemperature of the thermocompression bonding is lower than 400° C., thesemiconductor die 110 and the substrate 120 might not be substantiallyadversely affected by the temperature of the thermocompression bonding.

Also for example, the pressure of the thermocompression bonding may bebetween 0.1 bar and 20 Kbar (or in the range from 0.1 bar to 20 Kbar).In this case, if the pressure is higher than 0.1 bar, the positions ofthe conductive interconnection structures 111/121 may be efficientlyfixed when the intermetallic compound is formed using the conductiveinterconnection structures 111/121 and the ink. In addition, if thepressure is lower than 20 Kbar, deformation of the conductiveinterconnection structures 111/121 can be prevented (or reduced), forexample when the conductive interconnection structures 111/121 aremisaligned.

As shown in FIG. 2F, when the intermetallic bond is completely formedbetween the conductive interconnection structures 111/121, the interface125 may partially or virtually wholly disappear, resulting in thebonding region 130. In this manner, a semiconductor device having abonding region 130 in the final product resulting from the bonding ofthe conductive interconnection structures 111/121 (and/or metal parts ofthe ink) can be manufactured. The bonding region 130 may, for example,maintain a securely bonded state by forming an intermetallic compound(IMC), enhanced by the ink (or a portion thereof) positioned at aboundary between the conductive interconnection structures 111/121.Thus, the bonding region 130 may provide a higher bonding strength thanin the case of a bonding method using a conventional solder.

After the bonding has been completed, block 190 may comprise removingthe die manipulation tool 22 and the stage 40.

In general, block 190 may comprise bonding the semiconductor die to thesubstrate. Accordingly, the scope of this disclosure should not belimited by characteristics of any particular bond or any particularmanner of forming such bond.

The example method 101 may comprise continuing execution at block 195.Block 195 may, for example, comprise directing execution flow of theexample method 101 to any block (or step) of the method 101 (or portionthereof). Also for example, block 195 may comprise directing executionflow of the example method 101 to next steps for forming a semiconductorpackage, for example, encapsulating the bonded conductiveinterconnection structures 111/121 in an underfill and/or moldingmaterial, stacking one or more additional dies on the assembly,encapsulating the package, back-grinding or otherwise thinning the die110 and/or the substrate 120, etc.

Various aspects of the present disclosure will now be presented in thecontext of photographic images. In particular, FIGS. 3A to 3B showillustrative cross-sectional drawings and/or images of an electronicdevice in accordance with various aspects of the present disclosure.

The example images of FIGS. 3A to 3B show bonding regions 130 betweenthe semiconductor die 110 and the substrate 120. As shown in FIGS. 3Aand 3B, the metal-to-metal bond (e.g., copper-to-copper bond,copper-to-copper bond with silver particles, etc.) formed between theconductive interconnection structures 111/121 is efficiently formedutilizing the methods discussed herein. In fact, the bonding region 130(and/or the original interface 125 that existed when the conductiveinterconnection structures 111/121 were initially brought into contact)between the conductive interconnection structures 111/121 may bechallenging to detect in various scenarios without, for example, anenergy-dispersive spectroscopy (EDS) analysis.

As discussed herein, the bonding region 130 may comprise anintermetallic compound formed from the respective metals at the ends ofthe conductive interconnection structures 111/121 and from the metal(e.g., silver) in the ink. Thus, the bonding region 130 having a veryhigh quality may be formed utilizing a bonding process (e.g.,thermos-compression bonding) that does not include utilizing a soldermaterial and/or utilizing ultrasonic bonding techniques. In other words,the bonding region 130 may be formed in an economically efficient mannerand still have a very high quality. Additionally, the methods discussedherein provide for finer pitch interconnection structures than providedby other methods (e.g., solder-based methods, etc.) that may for examplerequire additional buffer space for the flow (or reflow) of bondingmaterial (e.g., solder flow, epoxy flow, etc.). The bonding region 130formed in accordance with various aspects of this disclosure also hassuperior electrical conductivity through the bonding region 130,enhancing the performance of the electronic device. The bonding region130 formed in accordance with various aspects of this disclosure alsoexhibits superior joint quality (e.g., enhanced bonding strength, lowjoint failure rates, etc.).

In an example implementation, the bonding region 130 may comprise a thinlayer of pure silver with no copper. The bonding region 130 may, in anexample implementation, comprise a thickness between 1 nm and 10 um. Forexample, the bonding region 130 may comprise a thickness between 1 umand 10 um. In another example implementation, the bonding region 130 maycomprise Cu—Ag intermetallic bonds and may also comprise Cu—Cuintermetallic bonds.

In summary, various aspects of this disclosure a method of manufacturingan electronic device and an electronic device manufactured thereby. As anon-limiting example, various aspects of this disclosure provide amethod of manufacturing an electronic device, and an electronic devicemanufactured thereby, that utilizes ink to form an intermetallic bondbetween respective conductive interconnection structures of asemiconductor die and a substrate. While the foregoing has beendescribed with reference to certain aspects and examples, it will beunderstood by those skilled in the art that various changes may be madeand equivalents may be substituted without departing from the scope ofthe disclosure. In addition, many modifications may be made to adapt aparticular situation or material to the teachings of the disclosurewithout departing from its scope. Therefore, it is intended that thedisclosure not be limited to the particular example(s) disclosed, butthat the disclosure will include all examples falling within the scopeof the appended claims.

What is claimed is:
 1. A method of manufacturing an electronic device,the method comprising: providing a substrate comprising a substrateconductive interconnection structure; providing a semiconductor diecomprising a die conductive interconnection structure protruding from afirst side of the die; coating at least a first surface of the dieconductive interconnection structure and/or at least a first surface ofthe substrate conductive interconnection structure with an ink thatcomprises metal; and bonding the first surface of the die conductiveinterconnection structure and the first surface of the substrateconductive interconnection structure.
 2. The method of claim 1, whereinthe substrate comprises a wafer or panel of substrates.
 3. The method ofclaim 1, wherein said providing the semiconductor die comprisesproviding a semiconductor wafer comprising the semiconductor die and oneor more other semiconductor dies, the method comprising after saidproviding, singulating the semiconductor die from the providedsemiconductor wafer.
 4. The method of claim 1, wherein the dieconductive interconnection structure comprises a metal pillar.
 5. Themethod of claim 1, wherein the first surface of the die conductiveinterconnection structure is non-planar.
 6. The method of claim 1,wherein said coating comprises coating at least the first surface of thedie conductive interconnection structure with the ink.
 7. The method ofclaim 1, wherein said coating comprises dipping at least a firstrespective surface of the die conductive interconnection structureand/or a first respective surface of the substrate conductiveinterconnection structure in the ink.
 8. The method of claim 1,comprising prior to said coating, singulating the semiconductor die froma semiconductor wafer, and wherein said coating comprises coating atleast a first respective surface of the die conductive interconnectionstructure of the singulated semiconductor die with the ink.
 9. Themethod of claim 1, wherein the metal comprises: metal ions, metalmolecules, and/or metal particles, dispersed in a solvent.
 10. Themethod of claim 1, comprising prior to said coating, forming the ink onan ink carrier structure, and wherein said coating comprises dipping atleast the first surface of the die conductive interconnection structureand/or at least the first surface of the substrate conductiveinterconnection structure in the ink.
 11. A method of manufacturing anelectronic device, the method comprising: providing a substratecomprising a substrate conductive interconnection structure; providing asemiconductor die comprising a die conductive interconnection structureprotruding from a first side of the die; and pressing a first surface ofthe die conductive interconnection structure and a first surface of thesubstrate conductive interconnection structure together with at leastone layer of ink at an interface between the first surface of the dieconductive interconnection structure and the first surface of thesubstrate conductive interconnection structure.
 12. The method of claim11, wherein said pressing comprises performing said pressing utilizing athermocompression bonding process.
 13. The method of claim 12, whereinsaid bonding utilizing a thermocompression bonding process comprisesperforming thermocompression bonding without ultrasonic vibration. 14.The method of claim 12, wherein said thermocompression bonding processcomprises performing thermocompression bonding at a temperature between25° C. and 400° C.
 15. The method of claim 12, wherein saidthermocompression bonding process comprises performing thermocompressionbonding at a pressure between 0.1 bar and 20 Kbar.
 16. The method ofclaim 11, wherein said pressing comprises pressing the first surface ofthe die conductive interconnection structure and the first surface ofthe substrate conductive interconnection structure together with onlythe ink between the first surface of the die conductive interconnectionstructure and the first surface of the substrate conductiveinterconnection structure.
 17. An electronic device comprising: asubstrate comprising a substrate conductive interconnection structure; asemiconductor die comprising a die conductive interconnection structure;and a solderless bonding region including a first end of the substrateconductive interconnection structure and a first end of the dieconductive interconnection structure, wherein the solderless bondingregion comprises: metal from the first end of the die conductiveinterconnection structure; metal from the first end of the substrateconductive interconnection structure; and metal from an ink.
 18. Theelectronic device of claim 17, wherein the first end of the substrateconductive interconnection structure and/or the first end of the dieconductive interconnection structure is non-planar.
 19. The electronicdevice of claim 17, wherein the substrate conductive interconnectionstructure comprises copper, the die conductive interconnection structurecomprises copper, and the metal from the ink comprises silver.
 20. Theelectronic device of claim 17, wherein the solderless bonding regioncomprises an intermetallic bond comprising the metal from the first endof the die conductive interconnection structure, the metal from thefirst end of the substrate conductive interconnection structure, and themetal from the ink.